Table 3.

Subject and ocular parameters of normal (LASIK candidate), keratoconus suspects, and keratoconus subjects.

	No KC	KC suspect	KC	p (N vs KCS)	p (N vs KC)	p (KCS vs KC)
n (subjects)	1130	400	548
Subject age (years)	18.6 ± 4.1	24.9 ± 3.8	29.3 ± 5.1	<0.001	<0.001	<0.001
Family history of KC	197 (17.4%)	93 (23.2%)	149 (27.1%)	0.009	<0.001	0.174
Corneal thickness < 500 µm	—	321 (80.25%)	520 (94.8%)	—	—	<0.001
Asymmetric bowtie	—	278 (69.5%)	493 (89.9%)	—	—	<0.001
Corneal steepening ≥ 47 D	—	356 (89%)	531 (96.9%)	—	—	<0.001
Skewed radial axis > 21°	—	160 (40%)	372 (67.9%)	—	—	<0.001
Posterior elevation	—	276 (69%)	487 (88.9%)	—	—	<0.001
I-S asymmetry	—	324 (81%)	504 (91.9%)	—	—	<0.001

N = no KC; KC = keratoconus; KCS = KC suspect; I-S = inferior-superior.